Cases reported "Hearing Disorders"

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1/33. noise analysis of real-life listening situations for maximal speech audibility in hearing aid fitting.

    This study attempts to prescribe hearing aid characteristics for one listening environment selected by an individual hearing aid user in order to provide better speech intelligibility than standard insertion gain prescriptions. The procedure is based on acoustic analyses of noise recorded by the user. The main purpose is to show the feasibility of the measurement and analysis procedure as a tool to investigate the consequences of the noise characteristics of everyday hearing aid use. The speech intelligibility Index (SII) is used as a criterion to optimize the insertion gain frequency response of the hearing aid. The results indicate that realistic background noise information is essential to achieve the best possible speech audibility. Maximizing the SII required higher insertion gain above 5000 Hz than assumed in conventional fitting procedures. Different insertion gain frequency responses are required for different listening conditions. The measurement procedure could identify acoustic listening conditions where hearing instruments would probably give no benefit.
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2/33. noise-induced neurologic disturbances in divers exposed to intense water-borne sound: two case reports.

    Divers may be exposed to intense noise underwater. Two cases of neurologic disturbances during experimental exposures to 15 min of continuous underwater sound are described. sound exposure in the first case consisted of a warble tone with center frequency of 240 Hz and a sound pressure level of 160 dB re 1 microPa. Symptoms during exposure consisted of somnolence, lightheadedness, and an inability to concentrate. No apparent effect on hearing was noted. In the second case, a center frequency of 1,000 Hz at 181 dB was used. Lightheadedness, inability to concentrate, agitation, and head vibrations were noted during the exposure. The diver also exhibited a temporary auditory threshold shift of 19.2 dB. In both cases, overt symptoms resolved within 30 min after exposure, but both divers reported recurrent symptoms days to weeks after the exposures. Medical histories and examinations, assessment of dive profiles, and breathing gas analysis failed to support a source other than the sound exposures to account for the symptoms observed. Potential mechanisms for the described symptoms are discussed.
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3/33. Otoacoustic emissions and auditory brainstem responses after neonatal hyperbilirubinemia.

    Severe hyperbilirubinemia often results in hearing loss. Behavioral audiometry, auditory-evoked brainstem responses (ABRs) and otoacoustic emissions (OAEs) were performed in three such patients in an attempt to localize the pathophysiology of this hearing loss. Behavioral audiometric findings in these patients (all male, 4, 15 and 25 years old) ranged from severe in the 4-year-old, moderate in the 15-year-old and slight in the 25-year-old. Where obtained, ABR wave V thresholds were elevated or ABR were absent. However, absolute and inter-wave latency measurements were not indicative of brainstem pathology. OAEs (transient and distortion product) could only be obtained in the high- or low-frequency ranges in these patients. Our findings suggest that at least some lesions producing hearing loss in severe hyperbilirubinemia are in the cochlea, especially at the outer hair cells. Finally, we found that only moderately elevated serum bilirubin levels (<20 mg/dl) may contribute to the development of sensorineural hearing loss.
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ranking = 1.8111630585928
keywords = wave, frequency
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4/33. The effect of midline petrous apex lesions on tests of afferent and efferent auditory function.

    OBJECTIVES: Historically, audiological procedures have focused on the assessment of the afferent (ascending) cochlear-VIIIth nerve system and have, for the most part, ignored the efferent (descending) auditory system. We report afferent and efferent auditory test results for two cases with a cholesterol cyst of the right petrous apex; one lesion involves the afferent segment of the auditory system, and the second lesion involves both the afferent and efferent segments of the auditory system. These "natural experiments" provide a unique opportunity to study the effect of a space-occupying lesion of the petrous apex on afferent and efferent function of the auditory system. DESIGN: Transient evoked otoacoustic emission (TEOAE) suppression studies were performed to assess the effect of the cholesterol cyst on the efferent system of the two cases. In addition, three complementary afferent tests of brain stem auditory function were administered: 1) acoustic reflex thresholds (ARTs); 2) masking level difference (MLD); and 3) auditory brain stem response (ABR). These tests are complementary because the superior olivary complex (SOC) is involved not only in the mediation of the sound evoked efferent reflex assessed in TEOAE suppression, but in the mediation of the ARTs, the MLD, and the ABR. RESULTS: The two cases with midline petrous apex lesions, one not involving the VIII-cochlear efferent auditory system, differed from each other with regards to TEOAEs suppression, and ARTs. Specifically, the case with only afferent involvement produced normal TEOAE suppression, a normal MLD, normal ARTs, and abnormal waves III and V of the ABR, whereas the case with both afferent and efferent involvement produced abnormal TEOAE suppression, a normal MLD, abnormal ARTs, and abnormal waves III and V of the ABR. CONCLUSIONS: These cases illustrate that although several auditory tests can be mediated within the same or adjacent anatomical structures, i.e., the SOC, they may not be equally affected by the same lesion due to different physiology. Further, the TEOAE suppression paradigm is a clinically relevant test to assay the sound evoked efferent reflex that is mediated by the medial olivocochlear system of the SOC.
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ranking = 1.3111630585928
keywords = wave
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5/33. Pineal region tumor manifesting initially as hearing impairment.

    An 18-year-old male presented with a pineal region germinoma with hearing impairment as the chief complaint. Magnetic resonance image demonstrated a well-enhanced multi-cystic tumor extending into the upper fourth ventricle and wall of the bilateral lateral ventricles. audiometry revealed bilateral mild hearing impairment in the low frequencies. Auditory brainstem response recording showed low amplitudes in all waves (IV-V/I ratio < 1) with prolong latencies (I-V and III-V) on the right but no discernable wave at 60 dB clicks on left. Hearing impairment and audiometric findings were improved after ventriculoperitoneal shunt operation. The hearing impairment appeared to be a mixed (conductive and sensorineural) type. The tumor was responsible for the sensorineural deafness because of invasion and compression of the central auditory structures. The inferior brachium was maximally compressed anterolaterally by the dilated bilateral lateral ventricles and posteromedially by the tumor. hydrocephalus caused conductive deafness by halting or arresting the footplate of stapes movement, as a consequence of high-pressure transmission through the cochlear aqueduct.
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ranking = 1.3111630585928
keywords = wave
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6/33. Delayed visual maturation associated with auditory neuropathy/dyssynchrony.

    Delayed visual maturation is a term used to describe infants who initially seem blind but subsequently have a marked improvement. The mechanism of visual loss and the subsequent improvement remains unknown. Auditory neuropathy/dyssynchrony is a condition of hearing impairment associated with absent or severely abnormal brainstem auditory evoked potentials but normal cochlear functions as measured by otoacoustic emissions. In this report, a 9-month-old infant who had no visual fixation for the first 3 months of life and congenital hearing impairment is described. Her brainstem auditory evoked potential study at 2.5 months of age showed no response to click stimuli presented at 90 dB nHL, whereas her otoacoustic emissions were normal. Subsequently, her vision and hearing improved. A brainstem auditory evoked potential study at 9 months of age showed reproducible waveforms. This case suggests the need for a detailed hearing evaluation of children with delayed visual maturation. Furthermore, this case highlights the need for follow-up brainstem auditory evoked potential testing prior to pursuing any audiologic intervention.
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ranking = 0.65558152929641
keywords = wave
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7/33. The feasibility of using oto-acoustic emissions to monitor cochlear function during acoustic neuroma surgery.

    The feasibility of using evoked oto-acoustic emission (EOAE) measurement for intra-operative monitoring of cochlear function was assessed during removal of an acoustic neuroma in a 53-year-old woman with normal hearing on the operated side prior to surgery. The high level of noise in the operating theatre was the only material problem encountered and this was not sufficient to prevent recording of identifiable waveforms. During manipulation of the brainstem, damage to the cochlea was indicated by an increase in EOAE latency and its eventual disappearance. A total hearing loss in the operated ear was revealed after surgery. Monitoring cochlear function with EOAEs is probably best considered at present as an adjunct to auditory brainstem response monitoring of the composite cochlea and eighth nerve, thus providing differential information.
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ranking = 0.65558152929641
keywords = wave
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8/33. Portable stimulus generator for obtaining high-frequency (8-14 kHz) auditory brainstem responses.

    Currently, the most useful application of high-frequency (greater than or equal to 8 kHz) auditory evaluation is for serial monitoring of patients receiving potentially ototoxic agents. Many individuals, however, are unable to respond to behavioral auditory test techniques. An objective evaluation method such as the auditory brainstem response (ABR) is valuable with difficult-to-test individuals. Laboratory instrumentation has been demonstrated to evoke high-frequency-specific (8-14 kHz) ABRs with reliable intrasubject latencies over time. This instrumentation is limited, however, because it cannot be transported to the patient confined to a hospital room. A portable device has now been constructed to deliver high-frequency (8-14 kHz) tone-burst stimuli comparable to the lab system. This digital/analog high-frequency tone-burst stimulus generator weighs less than 5 pounds. It can be utilized with any ABR signal averager capable of generating a positive (condensing) click at approximately 4.8 volts. Case studies are presented to demonstrate the frequency-specific responses obtained with these high-frequency tone-burst stimuli.
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keywords = frequency
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9/33. aicardi syndrome accompanied by auditory disturbance and multiple brain tumors.

    We described a 5-month-old girl with aicardi syndrome accompanied by auditory disturbance and multiple brain tumors. She was admitted to our hospital because she suffered from intractable flexor spasms. physical examination revealed craniofacial asymmetry, left auricular deformity, scoliosis, and remarkable hypotonia with psychomotor retardation. Abnormal ophthalmological findings included chorioretinopathy with pale and round-shaped peripapillary lacunae, and there was modified hypsarrhythmia in her EEG. MRI revealed multiple brain tumors in the 3rd and the lateral ventricles which are considered to be choroid plexus papilloma with agenesis of the corpus callosum. ACTH therapy was administered because of the intractable seizures. After ACTH therapy, the thresholds of waves I and V were much improved. The interpeak latency of waves I-V of the left ear and the peak latency of wave I of the right ear had been lengthened. Acoustic reflex with contralateral stimulation showed no response in the left ear. These findings indicate that the auditory system is also involved in the aicardi syndrome and that ACTH is effective for its dysfunction.
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ranking = 1.9667445878892
keywords = wave
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10/33. water may cure patients with meniere disease.

    OBJECTIVES/HYPOTHESIS: We examined whether sufficient water intake is effective in the long-term control of vertigo and hearing activity in patients with meniere disease (MD) for whom conventional therapy has proven unsuccessful. STUDY DESIGN: The authors conducted a time-series study with historical control. methods: Eighteen patients with MD in group 1 drank 35 mL/kg per day of water for 2 years. Twenty-nine patients with MD treated with the conventional dietary and diuretic therapy for more than 2 years during 1992 to 1999 at the same hospital were enrolled in a historical control of group 2. RESULTS: patients in group 1 dramatically relieved vertigo and significantly improved in the hearing of the worst pure-tone average of three frequencies (0.125, 0.25, and 0.5 kHz) (low PTA) during the last 6 months of the study period. In contrast, patients in group 2 became worse in both the four- (0.5, 1, 2, and 4 kHz) frequency PTA and the low PTA, although their vertigo did improve. The number of patients whose hearing were improved, unchanged, and worse were 4, 12, and 2 in group 1 and 2, 11, and 16 in group 2, respectively. CONCLUSION: Deliberate modulation of the intake of water may be the simplest and most cost-effective medical treatment for patients with MD. Larger studies will be needed to confirm these results in a larger patient cohort.
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